I have MySQL, php and Apache installed on my machine and I'm having problems enabling cookies, so that I could test my site before I upload it to the real server. I've edited configs of apache and php and set everything I could find about cookies to yes, but it doesn't work.

Generally speaking, to get cookies to work, there's nothing to configure on the server side. A vanilla installation of PHP/Apache should work just fine without any tweaking. What exactly are you trying to do with cookies? Can we see the part of your code that deals specifically with cookies?